Memory Compression Cache

[Ranjna Aggarwal]

Whatever the memory compression cache is for per vm that is deducted from the memory allocated to the vm or this is other than the memory allocated to per vm?

[a_p_]

ESXi uses host memory for the compression cache.

see http://www.vmware.com/files/pdf/mem_mgmt_perf_vsphere5.pdf (page 11) for details.

André

[nrlparasher]

Hi Ranjana that is deducted from the memory allocated to the vm.

[Ranjna Aggarwal]

That means what u r saying according to that if 2gb RAM is allocated to an vm then 10% that is 200mb is deducted and only near about 1800mb RAM will be available to the VM.

Now my doubt is:

is it reserved? or deducted only when memory compression is required?

[nrlparasher]

It's not deducted only exist when memory compression is required.

[Ranjna Aggarwal]

Then how much RAM will be available to the VM normally.

[a_p_]

Did you see the document I attached in my previous post?

André

[nrlparasher]

Compression is done only of the pages which will be otherwise be swaped, The VM at any time if required can use complete allocated memory.

[beckham007fifa]

Ranjna Aggarwal wrote:

Then how much RAM will be available to the VM normally.

Only pages that would otherwise be swapped out to disk are chosen as candidates for memory compression.